/**
 * This file is part of 1genia trampoline
 * Copyright (C) 2007 1genia (contact@1genia.com)
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; version 3 of the License. 
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details. 
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; see the file COPYING.TXT.  If not,
 * write to the Free Software Foundation, Inc., 51 Franklin Street,
 * Fifth Floor, Boston, MA 02110-1301, USA. 
 **/
package com.genia.toolbox.web.gwt.form.client.widget.item.impl;

import java.util.List;

import com.genia.toolbox.web.gwt.basics.client.i18n.GwtI18nMessage;
import com.genia.toolbox.web.gwt.form.client.validator.ValidatorCallback;
import com.genia.toolbox.web.gwt.form.client.widget.item.ItemWidget;

/**
 * Default ValidatorCallback that display the errors.
 */
public final class DisplayErrorValidatorCallback
    implements ValidatorCallback
{
  /**
   * the widget that is checked.
   */
  private transient final ItemWidget widget;



  /**
   * constructor.
   * 
   * @param widget
   *          the widget that is checked
   */
  public DisplayErrorValidatorCallback(final ItemWidget widget)
  {
    this.widget = widget;
  }



  /**
   * this method is called after the validation has ended.
   * 
   * @param result
   *          is the result of the validaiton. It is <code>null</code> or an
   *          empty List when the value was valid and is the list of error
   *          messages as
   *          {@link com.genia.toolbox.web.gwt.basics.client.i18n.GwtI18nMessage}
   *          when the value was invalid.
   */
  public void validationResult(List<GwtI18nMessage> result)
  {
    if (result == null || result.isEmpty()) {
      widget.setErrorMessage(null);
    }
    else {
      widget.setErrorMessage(result.get(0));
    }
  }
}
